Investigation on the Thomas Fire Impacts in Santa Barbara County, CA (2017 - 2018)¶
Leveraging MPC Landsat Collection 2 level-2 data & County Level AQI reports to assess burned areas and public health conditions.¶
Author: Sofia Ingersoll¶
Published: 2023-11-12¶
🗃️GitHub Repo: https://github.com/saingersoll/Thomas_Fire_Investigation¶
Google earth V 6.2.2.6613. (December 13, 2017). Santa Barbara, United States. 34.6099° N, 120.0665° W, Eye alt 13.72 feet. DigitalGlobe 2020. http://www.earth.google.com [December 12, 2023].
The Thomas Fire¶
On December 4, 2017, a Santa Ana wind event with historic duration swept throughout Ventura and Santa Barbara County with an average speed of 32 m/s and early gusts as high as 35 m/s (Fovell, Gallagher, 2018). Southern California's Mediterranean climate creates an abundance of ample fire-fuel during the highest stress period for vegetation, typically between July and the first rain fall following summer (Nauslar, Abatglou, Marsh, 2018). As a result of frequent, unprecedented wildfires invasive weeds and grasses, also known as "flashy fuels", dominate large land parcels making them more fire prone (National Parks Service, 2023). These combined factors, alongside weakened and outdated electrical infrastructure introduce high wildfire risks throughout large portions of the state. Soon after the Santa Ana winds picked up, a "line slap," was shared between Southern California Edison ("SCE") powerlines, sparking hot materials which then ignited a nearby fire-fuel bed (Ventura County Fire Department, 2019). This rapidly developed into the Thomas Fire, and within hours, the same circuit was also responsible for the Woolsey Fire, and Koeningstein Fire (Ventura County Fire Department, 2019).
All together, these fires devistated both Ventura and Santa Barbara County for a total of 40 days. The Thomas Fire alone consumed total of 281,893 acres; destroying 1,063 structures and claiming two casualties (one civilian and one firefighter) (CAL FIRE, n.d.). Though, even greater losses occured in January 2018, as a result of mudslides in the areas impacted by the fire. Unfortunately, 23 lives were lost due to debris flow in Montecito (Wildfire Today, n.d.; California Govenor's Office of Emergency Services, n.d.). As of 2019, SCE agreed to a $360 million settlement to address the conglomorate negative impacts caused by the Thomas Fire, Woolsey Fire, and Koeningstein Fire. To help reduce wildfire risks and prevent a similar trajedies, utility companies across the state have invested in strucutral hardening (Lazo, 2024). Although, that is not the only proactive wildfire mitigation tactic being exercised. Members of the USDA Forest Service and the California Air Resources Board (CARB) are devoted to identifying areas with surplus fire-fuel accumulation to conduct prescribed ("Rx") burns. Further implementation of proactive land managment practicies can strengthen California's resiliency against extreme and unprecedented weather events. Thus securing greater safety and security for its natural spaces, structures, and residents.
Objective¶
To gain a better understanding of the initial environmental and public health impacts primarily caused by the Thomas Fire, we will:
Quanitfy and visualize the amount of wildfire air pollution in Santa Barbara County between 2017/01 - 2018/10 using the Daily AQI and the average AQI over a 5 day rolling window in units of ppm.
Examine the burn scar using false-color imaging (red, green, blue, near-infrared and shortwave infrared bands) from the Landsat-2 Collection 2 Level-2 atmosperically corrected surface reflectance satellite data from the Microsoft Planetary Computer ("MPC").
Outcome¶
The figure on the left displays the mean AQI ratings with respect to the AQI Health Guidelines. A sharp peak is observed the day the Thomas Fire began (Dec. 4, 2017) which falls within the Very Unhealthy category. Whereas the a 5 day period average was primairly in the Unhealthy category. This trend can be observed at the noted location in the figure below, indicating negative public health effects on air quality resulting from the Thomas Fire in combination with neighboring fires. The figure on the right, displays the large parcel of Santa Barbara County that was engulfed by the fire, explaining the uptake in particulate matter observed in December of 2017. There were detrimental direct impacts on public health and safety in terms of air quality as a response to these fires.